Testing system



April 14, 1925.

1,533,195 E. R. LUANDIUS TESTING SYSTEM Filed Dec 6,1923 2 Sheets-Sheet 1 f7; //7ve/1/0/1' [7/6 [and/us fly V I i A/fy.

April 14, 1925.

1,533,195 E. R. LUNDIUS TESTING SYSTEM Filed 'Dec. 6

//71 e/1/0/ fr/c fi. 10/147215 Patented Apr. 14, 1925.

f UNITED STATES PATENT OFFICE.

ERIC R. LITNDIUS, OF RICHMOND HILL. NEW YORK, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TESTING SYSTEM;

Application filed December To all whom it may concern:

Be it known that I, ERIC R. LUNDIUS, a citizen ofthe United States of America, residing at Richmond Hill, in the county of Queens and State of New York, have invented certain new and useful Improvements in Testing Systems, of which the following is a full, clear, concise, and exact description.

The present invention relates to telephone exchange systems, and more particularly to means for testing portions of the equipment of telephone systems employing automatic switches for the establishment of connections.

In machine switching telephone exchange systems calls for unequipped lines are auto- .matically directed to what is called an intercepted operators position. This operatoris provided with cord circuits for answering such calls as well as calls intercepted for other reasons. Among the functions required to be performed by such cord circuits are supervision, recall of the operator, recall of a distant operator, ringing on revertive calls, extending a call to a subscribers line, ringing on that line, etc. In order that such cord circuits may function properly at all times, it is necessary to subject their various parts to frequent tests.

It is the object of the present invention to provide means which shall be simple, efiicient and rapid in operation by which i such operators cord circuits may be tested.

feature of the invention lies in the combination, in a single portable organization, of the circuits necessary to perform. all the tests which it is desired to make on such cord-circuits. I

Another feature of the invention lies in the provision of a progressive switch for successively associating the cord circuit with the necessary apparatus to perform the various tests.

A further feature of the invention lies in a progressive arrangement of the tests so that they may be made with the greatest etliciency and rapidity.

A particular feature of the invention lies in means for associating the cord circuit to be tested with any one of the test circuits of the testing device.

These and other features of the invention will be more clearly understood from. a consideration of the followingdescription 6, 1923. Serial No. 678,933.

together with the accompanying drawings and appended claims.

In the drawings, Fig. 1 shows a cord circuit of the type above described; Fig. 2 shows a test set whereby said cord circuit may be submitted to a plurality of tests.

The cord circuit shown in Fig. 1 is of the general type disclosed in the patent of John IV. Gooderham, No. 15053231 issued Aug. 12, 192 1. In addition to the functions above mentioned, this particular cord circuit is also equipped to handle calls where the subscriber calls the operator directly, such as calls for assistance, etc.

The purposes of the various portions of the cord circuit 100 are briefly as follows: plug 101 and its associated apparatus from the answering end of the cord; sleeve relay 102 operates whenever plug 101 is inserted in a jack associated with an incoming line, but marginal sleeve relay 103 operates only in connection with intercepted calls. The left winding of supervisory relay 105 has a high resistance while the right winding of that relay has a low resistance. On intercepted calls from a machine switching ofiice, with relay 103 operated relay 105 functions through its high resistance winding. On direct calls relay 105 functions through its low resistance winding and feeds battery to the subscribers line. On intercepted calls machine ringing is tripped as soon as the listening key 107 is operated, relay 108 initiating the tripping operation. Relays 122 and 123, under the control of the contact of interrupter 124, serve to close the circuit of tripping relay 112, and-relay 121, operating in response to the next closure of the contact of interrupter 124, serve to open that circuit. slow to release, bridges resistance 126 across the trunk circuit for a period measured by the successive closures of the contact of interrupter 12 1 and the releasing time of relay 112, which is so adjusted as to permit the tripping of the machine ringing, but not the collection of a coin or the operation of a message register at the machine switching oilice. In the case of a direct cal with relay 110 deenergized, relay 121 is operated i1nmediately after the closure of the listening hey, preventing the tripping operation. If a subscriber, having talked with the operator, hangs up and immediately thereafter removes his receiver to recall the operator,

Tripping relay 112 which is or merely depresses and releases his switchhook for thatpurpose, supervisory lamp 106 1s flashed and buzzer 118 sounded .through the agency of interrupter 109. Relay 129, which .is'operated'under the control of re-.

lay 116, serves to extend the talking conductors to the operators telephone set 130.-

Key 11 1 serves a double purpose, that of flashing the supervisory signal. of an operator by means of whom a call may have been extended to this position and, in conjunction with the master ringing key (not shown), to ring back on revertive calls. Keys 145' and 161 serve, respectively, to collectand refund coins which may have been deposited in the extension of a call to this position.

Plug 131 and its associated apparatus constitutes the'calling end of the cord circuit 100. The sleeve relay'138 operates on the insertion of plug 131 in an outgoing jack to close the tip conductor of the cord and to light the supervisory lamp 132. Marginal sleeve relay 139 is not ordinarily operated but it the operator should by mistake use the, calling end of the cord to answer an intercepted call, it would operate, in turn operating relay 13 1 to open the ring conductor and prevent an operative connection. Supervisory relay 137 serves to retire lamp -132-wlien a connection has been established.

Key 135 connectsv dial 150 and relay 1 19 across the outgoing end of the cord circuit to permit the establishment of connections over the machine switching-central ol'lice apparatus. Relay 149 is operated when such apparatus [is in condition to receive dial pulses and'operates relay 152 to extend the dial tone to the operators circuit 130. :Key 136 1s the ringing key for use on outgoing-connections.

mThe test-set shown inFig. 2 is provided with three jacks by .means of which the by the cord circuit attached thereto may be tested.

Brush 203 and the set of terminals engaged thereby complete circuits for lightmg the group of progress lamps 218, 221, etc. there being a lamp corresponding to "each of the-tests which is to be applied.

Lamps 202 and 277 mark the posit-ions of the switch from which tests on the answer- .ing' cord and the calling cord, respectively,

are begun. here the same tests are made on both answering and calling cord, the same lamp is lighted for both ends of the cord circuit. Lamps 253, 222, 259 and 306 are test lamps. Lamp 222 is lighted as an indication that some lamp in the cord circuit should be lighted. Lamp 253 is lighted in response to action produced in the test set by the'cord circuit, while lamps 259 and 306 are lighted at the time that flashing and flashing recall are tested. Brushes 203, 209, 269 and 225 of. switch 200 are bridging brushes, that is, make contact with one terminal before leaving the one just preceding. Brushes 234 and 229 are non-bridging, that is, break Contact between terminals. Key 205 is used for energizing the stepping magnet ot' switch 200 and serves to step the switch to a position to associate any desired one of the test circuits with the cord circuit under test. The special function of the keys or switches shown at the lower'left corner of the figure will be more clearly understood from the detailed description given hereinafter. Keys 239, 205 and 217 have only one pair of springs and are nonlocking. Switches 210 and 211 have two pairs of springs and normally engage one of such pairs. Although for simplicity battery isshown permanently connected to the resistances through which the lamps are lighted, according to the usual custom this battery'would be connected to the test circuits by a plug and jack.

A more detailed description of the, operation of the circuits will now be given. \Vhen a cord circuit such as is to be given a complete test, the answering plug 101 is first inserted injack 201; It switch 200 is standing with its brushes engaging their normal terminals, lamp 202 will be lighted in' a circuit from battery, resistance .204, lamp 202, normal contact and brush 203t0 ground. other position, the lamp corresponding to that position will be lighted in asimilar circuit. It the switch is standing in any of the positions from 1 to 10, the operation of key 21"- will close a circuit from battery through the winding and back contact of stepping magnet 207. brush 269 and the terminal on which it is standing, conductor 276' to ground at the lowermost contact of key 217. Switch 200 will be advanced under the control of this circuit to its No. 11 position which will be indicated by the lighting of lamp 277. Another depression of key 217 will advance the switch to position 12 from which it will he stepped back to normal in a circuit from battery, winding and back contact of magnet 207, conductor 268, brush 269 and its No. 12 to 21 contacts, lower contact of iack 201 to ground.

When switch 200 has reached its normal position as indicated by the lighting of .3

If the switch is standing in any released.

lamp 202, key 205 may be depressed and The closure of the key completes a circuit from ground, lower contact of key 205, conductor 206, winding of stepping magnet 207 of switch 200 to battery, in which circuit magnet 207 operates. The release of key 205 permits magnet 207 to retract its armature and advance the brushes of switch 200 onto the- 1 o. 1 terminals of With their corresponding contact banks.

H switch 200 in this position, relay 102 of the be, lighted in the cord circuit.

cord circuit is automatically given a nonoperate test. A circuit may be traced from battery, winding of relay 102, winding of relay 103, sleeve of plug 101, sleeve of jack 201, conductor 208,-brush 209,- conductor 278, contact 279 of switch 211, resistances 212, 213, 214 and 2155, contact 216 of key 217 to ground Resistances212-215 are of such value as to produce a current through relay 102which should just fail to operate it. If the-relay is properly adjusted no lamp will Since relay 103 is marginal the current will be still less able to operate that relay. Lamp 218 will be operated to indicate the test which is being made. If relay 102 operates falsely,

7 lamp 106 will be lighted in an obvious circuit and adjustments can be made to bring relay 102 into the proper condition.

' .Key 205 is again depressed and released to close the above traced circuit of magnet 207 to step the brushes of switch 200 onto their No. 2 terminals. Lamp 221 is lighted in this position of switch 200 indicating an operate test on sleeve relay 102. The circuit of relay 102 is as above traced as far as brush 209 and from thence extends over the No. 2 contact, conductor 288, contact 219 of switch 211, thence through contact 220 of switch 210 in parallel with resistance 227, through resistances 213, 21 1 and 215, contact 216 of key 217 to ground. The current in this circuit is suflicient to operate relay 102, but stillinsuflicient to operate relay 103, and lamp" 106 i is lighted. .Lamp 222 .is also lighted in a circuit from battery through resistance 223, lamp 222, conductor22 1, conductor 264, No. 2 terminal and brush 225 to ground. The lighting of lamp 222 is a signal to the operator that a lamp of the cord circuit should be lighted at this time.

Switch 210 may now be thrown to its righthand position, opening the shunt around, resistancefi227 at contact 220. lVith resistance 227 inseries With'resistances 213, 21 1 and 215 the current through relay 102 is re duc'ed to a point where relay 102 will just remain operated and if that relay is properly adjusted lamp 106 should continue to be lighted. Switch 210 isnow restored to its left-hand position. l

The next test is applied to supervisory relay 105. Key 205 is. depressed and released as before and switch 200 is stepped on to its N o. 3 terminals. Sleeve relay 102 remains operated in this position in a circuit which is the same previously traced to brush 209 and-from thence extends over the N0. 8 contact through resistances 213, 214 and 215 to ground at contact 216 of key 217. For this test, listening key 107 is operated. At its middle upper contact key 107 closes a circuit from ground, conductor 170, winding of relay 108 to battery. Rclay 10S disconnects interrupter 109 from the front contact of relay 105 and completes a circuit for relay 120 extending from battery, winding of relay 120, left normal contact of relay 121, inner left front contact of relay 108 to ground at the right front contact of relay 102. Relay 120 closes a circuit'for relay 121 extending from battery, right winding of relay 121, front contact of relay 120, outer right contact of relay 108, outer left contact of relay 110 to ground at the right front contact of relay 102. Relay 121 operates and locks in a circuit from battery through its left winding, left alternate contact, inner left front contact of relay 108 to ground at the right front contact of relay 102 and in so doing opens the circuit of relay 120. At its right front contact relay 121 closes a circuit for relay 11(3 extending from battery right winding of relay 116, conductor 127, lowermost contact of key 107, conductor 128 to the right front contact of relay 121. Relay 116 operates. In position No. 3 of switch 200 a circuit for relay 105 is completed from battery through its right-hand low resistance winding, inner right back contact of relay 110, lower left winding of repeating coil 111, lower back contact of relay 112, contact 113 of key 11 1, ring of plug 101 and jack 201, conductor 228, brush 229 and its No. 3 terminal, conductor 230, resistance 231, through ontact 232 of switch 210 in parallel with resistances 237 and 238, No. 3 contact of brush 234, conductor 235, tip of jack 201 and plug 101, contact 115 of key 11 1, upper back contact of relay 112, left front contact of relay 102, upper left winding of repeating coil 111 to ground at the inner left back contact of relay 110. The current in this (ircuit is su'fiicient not only to operate relay 105 but to tl'ioroughly magnetize its core. The operation of relay 105opens the circuit of lamp 106 and that lamp is extinguished. Although a circuit is completed from ground through the left winding of relay 116. left front contact of relay 116, left front contact of relay 105, through lamp 106 to battery, the resistance of the winding of relay 116 is su'llicient to prevent the lighting of the lamp, although relay 116 is locked in the circuit. Switch 210 may now be thrown to its right-hand position removing the shunt around resistances 237 and 238. Vith these two resistances in the circuit of relay 105 that relay does not receive sufiicient current to remain operated and should release. The release of relay 105 again completes the circuit of lamp 106 r and that lamp should light. Vith switch 210 in its right-hand position, key 239 is depressed, short-circuiting resistances 231 and 238 to produce a current through the supervisory relay suliicient to operate it. The operation of relay 105 should again extinguish lamp 106. Key 239 is nowreleased and switch 210 restored to its lefthand position. During this test, lamp 236 is lighted in a circuit over brush 203.

Key 205 is again depressed and released and switch 200 is advanced to its No. 4 position. In this position, marginal relay 103 is tested. In position No. 4 the circuit for supervisory relay 105 is opened at the contact of brush 229. The circuit for relays 102 and 103 extends as previously traced to brush 209 and thence over the No. 4 contact through resistances 214 and 215 and contact 216 of key 217 to ground. The current in this circuit is sufficient to operate relay 102 but is just insufiicient to operate relay 103. Lamp 240 is lighted to indicate the test being made and lamp 222 is operated in a circuit from battery resistance 223. lamp 222, conductor 224, contact 241 of switch 211, conductor 281, No. 4 contact and brush 225 to ground, indicating that the lamp of the cord circuit should be lighted. The operation of relay 102 lights lamp 106 and the failure of relay 103 to operate permits its continued illumination.

Key 205 is momentarily operated to advance switch 200 to its No. 5 position. In

this position the above traced circuit for relays 102 and 103 extends as before to brush 209 and then over its No. 5 terminal (towhich are strapped the Nos. 6, 7 and 8 terminals) t-l'n'ough resistance 215 to ground at contact 216 of key 217. The current in this circuit is sufficient to operate relay 10" as well as relay 102 and these relays will remain operated throughout positions 5, 6. 7 and 8. -Relay 103 closes an obvious circuit for relay 110, which relay operates. opening-the circuit through the right-hand low resistance winding of relay 105 and closing a circuit through its left-hand high re.- sistance winding extending from battery through the left winding of relay 105, inner left front contact ofrelay 110, upper left winding of repeating coil 111, left front contact of relay 102, upper back contact of relay 112, contact 115 of key 114, tip of plug 101 and iack 201, conductor 235, brush 234 and its No. 5 terminal, resistance 242, contact 243 of switch 210 to ground. Supervisory relay 105 operates and opens the circuit of lamp 106. Since relay 116 is operated as previouslydescribed, lamp 106 is extinguished- None of the test lamps are and103 are operated at this time. If relay 110 has opened its back contacts and closed its front contacts, relay 105 is operated in a circuit from battery through the left winding of relay 105, inner left front contact of relay 110, upper left winding of repeating coil 111, left front contact of relay 102, upper back contact of relay 112, contact 115 of key 114,- tip of plug 101 and jack 201, conductor 235, brush 234 and its No. 6 terminal, resistance 242, contact 243 of switch 210 to ground. However, if relay 110 has not opened its back contact, another circuit is available from battery through the right winding of relay 105, inner right contact of relay 110, lower left winding of repeating coil 111, lower back contact of relay 112, contact 113 of key 114, ring of plug 101 and jack 201, conductor 228, brush 229 and its No. 6 terminal, conductor 245, resistance 246 to ground. In either case, lamp 106 will be extinguished. To test in which of these circuits relay 105 is operated, switch 2101s thrown to its right-hand position, opening the circuit through the left-hand high resistance winding of relay 105. If relay 110 has opened its back contact lamp 106 will be lighted since relay 105 will be released. If lamp 106 fails to light, this is an indication that relay 110 is not properly adjusted. At the completion of this test, switch 210 and key 107 are restored, the restoration of key 107 releasing relays 108 and 121. Relay 116 is held operated as long as relay 105 remains operated.

Key 205 is now momentarily depressed and switch 200 advanced to its No. 7 position. Lamp 256 is lighted to mark the test to be made, which, in this position, is I on the operation of the cord circuit in tripping machine ringing. In position "No. 7 both ofthe previouslytraced circuits for relay 105 are opened and that relay releases, in turn releasing relay 116. Relays 102 and 103 are maintained energized as described'in position No. 5. Another circuit is closed for relay 105 in position No. 7, which may be traced from battery, left winding of relay 105 and thence as previously traced to brush 234, its No. 7 contact, conductor 250, ring contact of jack 251, conductor 252, upper contact of key 205, resistance 246 to ground. Relay 105' reoperates in this circuit. Since listening key 107 is not now closed, a circuit is intermittently completed from battery through lamp 106, front contact of relay 105, left back contact of relay 116, outer left back to ground through the contact of interrupter 109. Lamp 106 fiashes and buzzer and ring conductors.

118 sounds in: response to-each closure of the contact of interrupter 109. The tester now "operates vthe listening key 107 and closes an obvious circuit for relay 108. The operation of relay 108 .closes a circuit for 120 as before. It also transfers the circuit of lamp 106 to ground through the winding of relay 119. Relay 119. operates, but due to its high resistance, lamp 106 is extinguished. Relay 119 closes a circuit from battery, winding of relay 122, left back contact of relay 123, contact of interrupter 124, contact of relay 119, leftnorma-l contact of relay 121, inner left contact of relay 108, conductor 104 to ground at the left contact of relay 102. At the first closure of. the contact of interrupter 124, relay 122 operates and closes a locking circuit for .itself through the Winding of relay .123, right front contact of relay 122, left normal contact of relay 121 and thence as above traced to ground. In the succeeding open period of the interrupter, relay 123 operates in this locking. circuit and completes a circuit for relay 112 extending from battery, winding of relay 112, outer right front contact of relay 110 conductor 163, normal contact of relay 125, inner right contact of relay 108, right contact ofrelay 123 to ground at the right back contact of relay 121. Relay 112 operates and bridges resistance 126' across the tip This closes a circuit for trip relay 249 in the test set, extending from source of ringing current 287, winding of relay 249, left back contact of relay 248, conductor 247, N o. 7 contact and brush 229, conductor 228, ring of jack 201 and plug 101, contact 113 of key 114, lower front contact of relay 112, resistance 126, upper front contact of relay 112, contact 115 of key 114, tip of plug 101 and jack 201, conductor 235, brush 234 and its No.

7 contact, conductor 250, ring contact of jack 251, conductor 252, upper contact of key 205, resistance 246 to ground. Relay 249 operates in this circuit, removing the shunt from the operating winding of relay 248 so that this relay operates in ,a circuit from battery, noninductive winding of relay 248 operating winding of relay 248, No. 7 contact andbrush 203 to ground. The operation of relay 248 lights lamp 253 from ground at the inner right contact of relay 248, lamp 253, resistance 254 tobattery.

When interrupter 124 again closes its contact, a circuit is completed from battery, through the right winding of relay 121, left front contact of relay 123, contact of interrupter 124, contact of relay 119, left normal contact of relay 121, inner left front contact of relay 108 to grounded conductor 104. Relay 121 operates and locks through its left winding and left alternate contact and the inner left contact of relay 108 to grounded conductor 104. The operation of circuit from battery relay 121 closes a through the right Winding of relay 116, conductor 127, lowermost contact of key 107, conductor 128 to ground at the right front contactof relay 121. Relay 116 operates and locks in a circuit from ground through its left winding and left front contact, left front contact of relay 105, lamp 106 to battery. The circuit of reL y 119 is opened and that relay releases. The operation of relay 116 also closes a circuit from battery through the winding of relay 129, right middle contact of relay 108, right front contact of relay 116 to grounded conductor 104. The operation of relay 129 closes the tip and ring conductors from the listening key 107 to the operators telephone circuit 130. The operation of relay 121 also opens the circuit of relay 120 and the.

locking circuit for relays 122 and 123, per mitting these relays to dee'nergize. The deenergization of relay 123 opens the circuit of relay 112 permitting this relay to deenergize and open the tripping bridge. When relay 112 closes its back contacts a circuit may be traced from source of ring ing current 287 through the low capacity condenser 255, left front contact of relay 248, conductor 247, No. 7 terminal and brush 229, thence over the ring conductor, through the repeating coil 111, back over the tip conductor to brush 234 and its No. 7 contact, conductor 250, ring contact of jack 251, conductor 25'2, upper contact of key 205, resistance 246 to ground. Ringing current induced in this circuit produces a tone in the right windings of repeating coil 111 which is extended through the contacts of key 107 and relay 129, to the operators telephone circuit 130. When this tone is heard by the tester, he is informed that the tripping feature has functioned properly. The listening key-107 is then restored releasing rela-ys108, 121 and 129.

Key 205 is again operated and released advancing switch 200 to position No. 8. In this position the flashing recall feature is tested. When brush 234 of switch 200 moves from position No. 7 to position No. 8, the circuit for relay 105 is opened and closed again simulating the action of the subscriber in recalling the operator. Relay 105 releases, opening the locking circuit of relay 116 and then is again operated. The circuit of relay 105 in position No. 8 is the same as previously described except that it extends through contact No. 8 of brush 234 instead of through contact No. 7, contacts Nos. 7 and 8 being strapped together. Relay 105 operates in this circuit and lamp contact of relay 226, No.

'106 fiashes in a circuit from battery, lamp 106, left front contact of relay 105, left back contact of relay 116, left hack contact of relay 108, winding'of relay 117 contact of at the cord circuit.

The flashing operation is also tested in this position; To do this the'calling plug 131 is-inserteol in jack 251. The insertion of plug 131 in jack 251' closes a circuit from battery, through the windings of relays 138 and 139, sleeve of plug 131 and jack 251, conductor 261 to ground through the winding of'relay 226. Relay 226 operates, dis-- connecting the source of ringing current 287 and lighting lamp 301 in-a circuit from battery resistance 223, lamp 306, inner right 8 contact and brush 225 to ground to match the cord lamp. Relay 138 also operates and closes a circuit for lamp 132 from battery through that lamp, hackcontact of relay 137, conductor 140, left front contact of relay 138 to ground, in which circuit lamp 132 lights. The calling'cord at this time acts as the calling cord of a distantoperator and the supervisory lamp 132takes the place of the lampat that operators position. Flash key 114 is now operated and a circuit is-closed from ground, contact164 of key 114, conductor 162, winding of relay 125 to battery. Relay 125 operates and closes a circuit from ground, front contact of relay 125, conductor 163, outer right contact of relay 110, which is operated since relay 103 is operated, winding of slow-to-release relay 112 to battery. "Relay 112 bridges resistance 126 across the tip and ring conductors of the answering cord; but as long as key 114 is held the conductors are open at the contacts of that key. and no circuit .is completed. When key 114 is releasechrelay 125 deenergizes, opening the circuit of relay 112, but

since relay 112 is slow-to-rel'ease, during the. releasing time of that relay. acircuit will he. I comp-leted'from battery," lower right winding of repeating coil :111, winding of relay 137 lower normal contacts of keys 136 and 135, contactof relay 134, ring of plug 131 and jack 251, conductor 250,'No. 8 contact and brush 234, conductor 235', tip of iack 201 and plug 101, contact 115 of key 114, upper front contact of relay 112,;resistance. 126, lower front contact of relay 112, contact 113 of key 114, rings of plug 101 and jack 201, conductor 228, brush 229 and its No. 8 contact, conductor 304 tip of jack 251 and plug 131, right front contact of relay 1'38, upper normal contacts of keys 135 and 136, upper right winding of repeating coil .111 to ground. Supervisory relay 137 operates in this circuit to open the circuit of lamp 132 andf'extinguish it.- As soon as relay 112 reslow-to-release character of relay 112 relay leases, this circuit is opened, relay 137 de-.- energizes and lamp 132 is again lighted. If key 114 is repeatedly depressed, clue to the the bridge 126 will bemaintained closed and 137 will follow the operation of key 114 to flashlamp 132. Lamp 259 continues to be lighted indicating that a flashing sig nal is to be expected. At the completion of the test, plug'131 is withdrawn from jack 251, releasing relays 137, 138 and 226, tinguishing lamps 132, 259 and? 301.

Key 205 is now operated and released to advance switch-200 to position'No; 9. In this positionthe coin refund and coin collect relays are tested. 'As soon as switch 200' arrives in position No. .9, lamp 262 is lighted. Lamp 222 is also lighted indicating that a lamp in the cord circuit is to be lighted. Coin'return key 161 is now operated to close a circuit from ground through the lowercontactof that lzey and the winding of relay 112 to battery. The operation of relay 112 again bridges resistance 126 across the tip and ring conductors. However, the operation of key 161 also closes a circuit from the source of negative coin return potential, through lamp 141, relay 142,

upper contact of key 161 to the upper front contact of relay112, thence over the tip of the line to brush 234 and its No[ 9 terminal, through resistances 263 and 265 130 ground. A direct path to ground is also closed over conductor 266 and contact 2740f switch 210 to ground in parallel with resistance 265. Relay 142 operates and lights the coin. pilot lamp143. To test the release of relay 142, switch 210 is thrown into its right-hand position, opening. the direct. path to ground and introducing resistance 265 in the circuit of relay 142. Relay 142 should releasein this rircuit extinguishing the coin pilot lamp 143. No'current flows-i over the ring conductor of the cord during this test, since the extension of that conductor is open atthe No. 9 terminal of brush 229. Switch 210 and key 140 are then released' Coin collect relay 144 is similarly tested, the circuit in this. case extending from positive source of potential through lamp 146, relay 144 and the upper contact of key 145 to the upper frontcontact of relay 112. The release of the relay is brought about in the same way as for relay 142.. Sleeve relay 102 is operated in position 9 over a circuit extending as before to brush 209, and thence over the No. 9 termi nal to ground through the winding of relayv 226. Relays 102 and 226 are both operated, relay 226, serving to hold source of ringing current 287 disconnected. Relay 103 .is not operated, due to the resistance of relay 226. No circuit is completed for relay 105. Lamp 106 is lighted when the coin keys are normal. I

Key 205 is again momentarily operated to advance switch 200 to its No. 10 position. In this position, a ringing test is made which is indicated by the lighting of lamp 302. Key 114 of the cord circuit and the master ringing key (not shown) are operated. A circuit is then completed from the source of ringing current 147, contact 148 of key 114, ring of plug 101 and jack 201, conductor 228, brush 229 and its No. 10 contact, alternating current buzzer 267, No. 10 contact and brush 234, conductor 235, tip of jack 201 and plug 101, contact 133 of key 114 to ground. Buzzer 267 sounds at each closure of key 114. The circuit for sleeve relay 102 is completed as before through the winding of relay 226 to ground.

net207, brush 269 and its No. 11 contact,

conductor 270, contact 271 of key 217 to ground, in which circuit switch 200 is stepped to its N0. 12 position. A circuit is then immediately closed over conductor 272 to ground at the lower contact of jack 201 and, since contacts 12 to 21 of the are served by brush 269 are strapped. together, stepping magnet 207 will be operated to automatically advance switch 200 back to its normal position, whereupon lamp 202 will be lighted and the tests just outlined may be repeated. If it is desired to repeat only one ora few of the tests key 205 may be repeatedly closed to advance the switch 200 to a position to associate the desired test circuit with the cord circuit.

However, if it is now desired to test the calling cord, plug 101 will be withdrawn from jack 201 and plug 131 inserted in jack 275; The insertion of plug 131 into jack 275 will automatically advance switch 200' into position 11 by means of a circuit extending from battery through the winding and back contact of stepping magnet 207, brush 269 and its No. 10 terminal, conductor 276, lower contact of jack 275 to ground, which circuit is interrupted as soon as the switch reaches its No. 11 position. In position No. 11, lamp 277 is lighted to indicate that the apparatus is ready to make tests on the calling cord.

Key 205 is now operated and switch 200* stepped to its No. 12 position. Since the plug has been removed from jack 201 the circuit previously traced for advancing the switch back to normal is open at this time.

In position No. 12 a non-operate test is made on sleeve relay 138. The circuit is com pleted from battery through the winding of relays 138 and 139, sleeve of plug 131 and jack 2,75, conductor 208, brush 209 and its No. 12 terminal, conductor 278, contact 279 of switch 211, resistances 212, 213, 214 and 215 to ground at contact 216 of key 217. Resistances 212-215 reduce the current in this circuit so as to just not operate relay 138. Lamp 218 is lighted as in the case of the non-operate test on the sleeve relay of the answering cord. None of the test lamps are lighted and it' relay 138 is properly adjusted, lamp 132 is not lighted.

Key 205 is now again operated and switch 200 advanced to its No. 13 position. In this position an operate test is made on the sleeve relay indicated by the lighting of lamp 221. Lamp is lighted over conductors 224 and 264 and No. 13 contact of brush 225 to ground. The circuit for relay 138 extends from the sleeve of jack 275, conductor 208, brush 209 and its No. 13 contact, conductor 288, contact 219 of switch 211, contact 220 of switch 210 in parallel with resistance 227, and then through resstunces 213, 214 and 215 to ground at contact 216 of key 217. \Vith resistances 213, 214 and 215 in the circuit, relay 138 should operate and lamp 132 should be lighted. Switch 210 may now be thrown to its righthand position, opening contact 220 and introducing resistance 227 in the circuit of relay 138 This resistance reduces the current to the lowest value which should hold relay 138 operated, and if that relay is correctly adjusted, lamp 132 remains lighted. Relay 139 is marginal and the currents at this time are not sufficient to operate it.

Key 205 is now operated to advance the switch 200 to its No. 14 position. In this position a circuit may be traced from battery, lower right winding of repeating coil 111, winding of supervisory relay 137, lower normal contacts of keys 136 and 135, contact of relay 134, ring of plug 131 and jack 275, conductor 228, brush 229 and its No. 14 terminal, conductor 230, resistance 231, contact 232 of switch 210 in parallel with resistances 237 and 238, No. 14 terminal and brush 234, conductor 235, tip of jack 275 and plug 131 right front contact of relay 138, upper normal contacts of keys 135 and 136, upper right winding of repeating coil 111 to ground. Relay 138 is maintained energized in position No. 14 in a circuit which is the same as that previously traced as far as brush 209 and then extends over the No. 14 contact, through resistances 213, 214 and 215. to ground at contact 210 of key 217. The continued energization of relay 138 holds lamp 132 lighted. Lamp 236 is lighted to indicate that the supervisory relay is under test. The circuit above traced for guished.

relay 137 through resistance 231 provides cuit is opened at the contact of that relay. Switch 210 may now be moved to its righthand position, removing the shunt from re sistances 237 and 238, thus reducing the current to a point Where relay 137 releases.

and lamp'132 is again lighted. ls ith' switch. 210 in its right-hand position, key is operated shunting resistances 231 and 238, increasing the current to the value which should operate relay 137. If that relay operates. lamp 132 is again extin- At the completion of these tests, switch 210 and key 239 are restored.

Key 205 is now operated to advance switch 200 to position No. 15 in which a non-operate test is made on the marginalv relay 139 as indicated by the lighting of lamp 240. The circuit of relay 139 is extended as before traced to brush 209, and thence through the No. 15 contact, resistances214 and 215 to ground at contact 216 in a circuit which extends as before to the is to bemade on a marginal sleeve relay.

The, circuit of relay 139 extends as before to brush 209 and from thence over its-No. 16 contact, through resistance 215 to ground at contact 216 of'key 217. Relay 137is held; operated in the circuit traced in position 15,

since terminals 15 and 16 in the banks associated with brushes 234 and 229 are strapped together. The current in the above traced circuit for relay 139 is sufficient to operate that relay and its operation closes a circuit for relay 134 which in turn opens the circuit of relay 137. \Vith the deenergization of relay 137, lamp 132 is caused. to light,

Lamp 222 is lighted at this time to indicate that the supervisory lamp should be lighted.

Key 205 is now depressed and released to advance switch 200 to its No. 17 terminals. In this position relay 149 is tested, lamp 303 being lighted to mark this test. Relay 138 is held operated, the circuit extending as before to brush 209 and thence over the Lamp 132 is extinguished" Supervisory relay No. 17' contact through resistances'213, 214 and 215, contact 216 of key217 to ground. Theinclusion of resistances 213 and 214 in this circuit prevents the operation of relay 139. Key 135 of the cord circuitis operated connecting'relay 149 and the dial 150 across the outgoing ends of the tip and ring conductors. "-The circuit of supervisory "re lay 137. is opened and that relay deenergizes. Therefore, with relays 139 and 137 deenergized, lamp 13.2 should'be lightedj A circuit is completed from ground on the No. 17 contact associated with brush. 234, brush 234, conductor'22-35, tip of jack 275 and plug 131, right'front contact of relay 138, upper alternate contact of key 135, conductor 155, through the winding of relay. 149, contact 151 of dial 150,.conductor 1.54, lower alternate contact of-key 135, back contact of relay 134. ring of plug 131 and jack 275,. conductor 228, brush 229and its No. 17 contact, conductors-284, and 285, outer left back contact of relay 228, contact 286 of switch 210 in parallel with resistance 282, through resistance 283 to battery. Relay 149 should operate in this circuit closing a circuit from ground at its contact, left back contact of relay 129, winding of relay 152 to battery. Relay 152 operates to extend the tip and ring conductors to the operators telephone circuit 130. A tone will be produced in the receiver 153, transmitted thereto over a circuit extending from source of ringing current 287, outer right back contact of relay 226, through low capacity condenser 255, conductor 284,170. 17 contact and brush 229, conductor 228, ring of jack 275 and plug. 133, back contact of relav 134, lower alternate contact of key 135. conductor 154, through the condenser 156, left front c0ntact of relay 152, conductor 158, thence through the telephone, circuit 130, back to conductor 157, right front contact of relay 152, contact 159 of dial 150, conductor 155, upper alternate contact of key 135, right front contact of relay 138, tip of plug 131 and ack 275, conductor 235, brush 234 and its No. 17 contact to ground. This tone willindicate that relay 149 has operated properly. Switch 210 is now moved to its righthand position, removing the shunt from resistance 282. With the addition of resistance 282 to the circuit of relay 149 that relay should release, opening the circuit of relay 129 and removing the tone from the telephone set 130. Switch210 and key 135v may now be restored.

Position No. 1.8 of switch 200 is not, in the present disclosure, equipped with any test circuit. Hence key 205 must now bedepressed and released twice advancing switch 200 to position 19 in which positionv ringing test is made. In this position the circuit for relay- 138 extends from brush 209 over the No. 19 contact to ground through the Winding. of relay .226. Relays 138end are operated, re 21y 226"d1scon necting source of ringing current 287. The

n km i opeietion-oi relziy 100 causes tue lighilng of the lamp 182. Lamp 302 is lighted to intest is being made R1115? flZlQQ properly, key 2i? is operated, advanc iositions hack to normal, in zrcircuit from ery, Winding and heel:

ductor 2'i2, Contact 273 of key 21'? to ground! As soon as switch 200'reaches normal position, t

closed -ndicutin that the a mratus is rend 12 I l to test another eordcwcrut or to repeat the of this circuit.

directly dialed callsymarginzil relay 1% is not operated. Also there IS no machine ringinglto be tripped. Hence il'COPti circuit intended solely for this type" of tritiiic would lack relays 103 and llO andthe tripping apparatus. lnconsequence, in testing such a cord ('lTCUIlI, the tests on the marginal relay and the trippingapparatus' would he omitted. T he test set shown in Fig.-

nmy be adapted for testing such a cord circuit by movingswitch211into its righthend position; With the switch in thisposition, the circuit of the sleeve relay extends from sleeve of incl: 201, conductor 208, bruslr 269 and by way of conductor278,-contect 281 of switch 211; conductor 292; resistances 289" and 29.0 in series; contact 216 of key 217 to to ground at contact 216 othey'2ll. In

position 3 the circuits'are'the SZHHGQSQJIGVl ously traced for the test of the supervisory relay. ,Vhen switch 200 is stepped into position-No. at {L circuit isclosed from battery through the Winding and back contact of stepping magnet 207, conductor 295, contacts 296 and 298 of switch 211, conductor 281, No. contact and brush 225 to ground. Switch 200 is stepped to position No. 5 in whi ch v *ing ascertained that ringing takes contact "of magnet 207', brush 269 and its 120x20 and 21' contacts. Winch arestrapped together, con-" he previous circuit for lamp 202"is l cord circuit 100 is used inconnection iroin thence; over the No. '1 contact,

battery through the Winding and back contact oi" magnet conductor 295, contacts 296; 298' and 300 of switch"2l1, conductor 22o to ground] tlu'oug'l positions Nos. 5,-(5 and? to p05? tiou NoJSWhere the fluslungrecail test-1s made as previouslydescribed. The remain- 9 the Nos. 5, 6 and terminals and thrush- Switch 200"- stepped ing tests are made in'subsequent positions above described. The switchfalso passes 207' ironrbuttery, windi'iigjiund beck 'con through the positions 'for testing; the' marginal relay; of the calling" cord; The momentary operation of key205 udvances' the switch froln'position 14C to positionrlfi )Vith switch 211 in its" rigl'it-hend position,

test of the magnet,"conductor 295; contacts:

296. 298,800 and 306 of switch21l,feonducto1: 30 No. 15 contact and brush 22fito ground,

in which circuitswitch 200is steppett'w pg sltion 16. In positlonl6 a circuit is'clo'sed' from butt'ery windingand buckcontncfiof magnet 20?, conductor 295, contacts 296j1nd 298 M suitch '2li, conducton28l, No.16 terminal and brush 226 to" ground, for step-f ping switch 200' into its No. 17 'position. llo circuit is completed for magnet 207111 position No. 1'? und switch2O0"'con1es to rest in position to test relay 149 of the cord circuit. Ringing test is nnule' inposition 19 as in thee/use of cord 100;"

The following is a tabulation of the tests. 'ios tions of switch 200 and signals displayed 1'01 correct functioning of the cord circuit Prog-- Positions'of Testy Signal 01 Testlalnp ress switchfloo cord circuit iight'ed' lamp lighted Normal (ani i V i 202 swering cord) 1 Relay 102-01011 21s operate). Relay 102 (oper 222 231.

fltfl). Relay 105'(lo\v"re- M 6 sistance winding). 1 Relay 103 (11011 222 240 operate). Relay 103 (operate) 244 Relay 105 (high 236' resistance windi ing).' 5 7 Tripping 106 (flash) 1 253 256 ('lonc). 8 Flash and (lush- 106 (flash) 259 and r ingi'ecell. 132'([1ash) 306. 9 Coin return and {143 211111441} 222 m2 coin collectv i 143 and 146 10 Revertive ringing;

ing. 11 (balling cord) 12 l 13fl(non-operatc);. 13 138 (operate) 14;. v 137.. 15 i 139(nou'opcratc)" l6... 131g (Operate) 1 From the ioregoing description and table, it Will be readily seen that a complete test position acircnit is completed froin'of the cord circuit may he made with this 13) arrangement in a very brief time. Should it become necessary. to ad ust any of the apparatus, the lamp indicating the point at which the tests have been stopped will remain lighted until the adjustment is completed, after which, the subsequent tests ma y be made. From the table it is evident that whenever aicord circuit signal should be operated to indicate the correct operation of the cord circuit, lamp 222 in the test set is displayed, and that special lamps indicate special tests. The lighting of lamp 132 in positions Nos. 17 and 19 is merely incidental to the tests being performed.

The values of the resistances included in the various circuits will be determined from the actual conditionswhich must be met by the cord circuit in practical operation.

What is claimed is:

1. In a telephone exchange system, a cord circuit, at test set comprising a plurality of test circuits, a progressively operable switch for successively associating said cord circuit with said test circuits, and means for operating said switch to associate said cord circuit with any one of said test circuits. 1

2. In a telephoneexchange system, a cord circuit, a test set comprising a plurality or test circuits, a progressively operable switch 7 for successively associating said cord circuit with said test circuits, means for operating said switch to associate said cord circuit with any one of said test circuits,

and means to indicate that said cord circuit and said test circuit have been so associated.

3. In a telephone exchange system, a cord circuit, a: test set'comprising a plurality of test circuits, a multi-position switch for associating said cord circuit with said test circuits and means for advancing said switch to a particular position to associate said cord circuit with a particular test circuit.

4;. In a. telephone exchange system, a cord circuit, a test set comprising a plurality of test circuits, a multi-position switch for associating said cord circuit with said test circuits, means for advancing said switch to a particular position to associate said cord circuit with a particular'test circuit, and means to indicate when said switch has arrived in such position.

5. In a telephone exchange system, a cord circuit, a testing device for testing said cord circuit comprising a plurality of test circuits, an automatic switch, manual means for advancing saids'witch to successively associate saidtestcircuits with a cord circuit.

and means to indicate which of said test circuits is efl ective.

6. In a telephone exchange system, a cord circuit having an answering end and a calling end, a test set comprising a multi-position switch, a plurality of test circuits adapted to be associated with the answering end of the cord circuit in one group of positions of said switch and a plurality of test tions'of said switch, and a plurality'ot test circuits adapted to be associated witn the calling endo't the cord circuit in another group of positions of said switch, means for .initiating the operation of said switch, and means actuated 1n response to the connection of one end of said cord circuit with said test set and the operation of said initiating means to automatically position said switch in the first of the group or positions corresponding to the end of the cert so connected.

8. In a telephone exchange system, a cord circuit having an answering end and a calling end, a test setcomprising a multi-position switch, a plurality. of test circuits adapted to be associated with the answeringend of the cord circuit in one group of positions 01' said switch, and a plurality of test circuits adapted to be associated with tl e calling end or the cord circuit in another group of positions of said switch, means for v initiating the operation of said switch, means actuated in response to the connection of one end of said cord circuit with said test set and the operation of said initiating means to automatically position said switch in the first of the group ct positions corresponding to the end of the cord so connecterhand means to indicate the arrival ct said switch in such. position.

In witness whereof, I hereunto subscribe my name this th. day of November A. 1).. 1923. i

mire n. LUNDIUH.

circuits adapted to be associated with the v 

